Hi
Side note: This fix requires
4e7aaa6b82d6 ("netfilter: ipset: Fix race between namespace cleanup and gc in the list:set type"
in first place, as a dependency.
Thanks
On Sat, Jun 22, 2024 at 07:41:24PM -0400, Sasha Levin wrote:
> This is a note to let you know that I've just added the patch titled
>
> netfilter: ipset: Fix suspicious rcu_dereference_protected()
>
> to the 6.9-stable tree which can be found at:
> http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
>
> The filename of the patch is:
> netfilter-ipset-fix-suspicious-rcu_dereference_prote.patch
> and it can be found in the queue-6.9 subdirectory.
>
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@xxxxxxxxxxxxxxx> know about it.
>
>
>
> commit 0226dfa53edc90463c1b0d50167da948c88025ef
> Author: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx>
> Date: Mon Jun 17 11:18:15 2024 +0200
>
> netfilter: ipset: Fix suspicious rcu_dereference_protected()
>
> [ Upstream commit 8ecd06277a7664f4ef018abae3abd3451d64e7a6 ]
>
> When destroying all sets, we are either in pernet exit phase or
> are executing a "destroy all sets command" from userspace. The latter
> was taken into account in ip_set_dereference() (nfnetlink mutex is held),
> but the former was not. The patch adds the required check to
> rcu_dereference_protected() in ip_set_dereference().
>
> Fixes: 4e7aaa6b82d6 ("netfilter: ipset: Fix race between namespace cleanup and gc in the list:set type")
> Reported-by: syzbot+b62c37cdd58103293a5a@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reported-by: syzbot+cfbe1da5fdfc39efc293@xxxxxxxxxxxxxxxxxxxxxxxxx
> Reported-by: kernel test robot <oliver.sang@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-lkp/202406141556.e0b6f17e-lkp@xxxxxxxxx
> Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxx>
> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
>
> diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c
> index c7ae4d9bf3d24..61431690cbd5f 100644
> --- a/net/netfilter/ipset/ip_set_core.c
> +++ b/net/netfilter/ipset/ip_set_core.c
> @@ -53,12 +53,13 @@ MODULE_DESCRIPTION("core IP set support");
> MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_IPSET);
>
> /* When the nfnl mutex or ip_set_ref_lock is held: */
> -#define ip_set_dereference(p) \
> - rcu_dereference_protected(p, \
> +#define ip_set_dereference(inst) \
> + rcu_dereference_protected((inst)->ip_set_list, \
> lockdep_nfnl_is_held(NFNL_SUBSYS_IPSET) || \
> - lockdep_is_held(&ip_set_ref_lock))
> + lockdep_is_held(&ip_set_ref_lock) || \
> + (inst)->is_deleted)
> #define ip_set(inst, id) \
> - ip_set_dereference((inst)->ip_set_list)[id]
> + ip_set_dereference(inst)[id]
> #define ip_set_ref_netlink(inst,id) \
> rcu_dereference_raw((inst)->ip_set_list)[id]
> #define ip_set_dereference_nfnl(p) \
> @@ -1133,7 +1134,7 @@ static int ip_set_create(struct sk_buff *skb, const struct nfnl_info *info,
> if (!list)
> goto cleanup;
> /* nfnl mutex is held, both lists are valid */
> - tmp = ip_set_dereference(inst->ip_set_list);
> + tmp = ip_set_dereference(inst);
> memcpy(list, tmp, sizeof(struct ip_set *) * inst->ip_set_max);
> rcu_assign_pointer(inst->ip_set_list, list);
> /* Make sure all current packets have passed through */
